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Diffstat (limited to 'arch/x86/mm/mem_encrypt_boot.S')
-rw-r--r--arch/x86/mm/mem_encrypt_boot.S80
1 files changed, 44 insertions, 36 deletions
diff --git a/arch/x86/mm/mem_encrypt_boot.S b/arch/x86/mm/mem_encrypt_boot.S
index 730e6d541df1..01f682cf77a8 100644
--- a/arch/x86/mm/mem_encrypt_boot.S
+++ b/arch/x86/mm/mem_encrypt_boot.S
@@ -22,9 +22,9 @@ ENTRY(sme_encrypt_execute)
/*
* Entry parameters:
- * RDI - virtual address for the encrypted kernel mapping
- * RSI - virtual address for the decrypted kernel mapping
- * RDX - length of kernel
+ * RDI - virtual address for the encrypted mapping
+ * RSI - virtual address for the decrypted mapping
+ * RDX - length to encrypt
* RCX - virtual address of the encryption workarea, including:
* - stack page (PAGE_SIZE)
* - encryption routine page (PAGE_SIZE)
@@ -41,9 +41,9 @@ ENTRY(sme_encrypt_execute)
addq $PAGE_SIZE, %rax /* Workarea encryption routine */
push %r12
- movq %rdi, %r10 /* Encrypted kernel */
- movq %rsi, %r11 /* Decrypted kernel */
- movq %rdx, %r12 /* Kernel length */
+ movq %rdi, %r10 /* Encrypted area */
+ movq %rsi, %r11 /* Decrypted area */
+ movq %rdx, %r12 /* Area length */
/* Copy encryption routine into the workarea */
movq %rax, %rdi /* Workarea encryption routine */
@@ -52,10 +52,10 @@ ENTRY(sme_encrypt_execute)
rep movsb
/* Setup registers for call */
- movq %r10, %rdi /* Encrypted kernel */
- movq %r11, %rsi /* Decrypted kernel */
+ movq %r10, %rdi /* Encrypted area */
+ movq %r11, %rsi /* Decrypted area */
movq %r8, %rdx /* Pagetables used for encryption */
- movq %r12, %rcx /* Kernel length */
+ movq %r12, %rcx /* Area length */
movq %rax, %r8 /* Workarea encryption routine */
addq $PAGE_SIZE, %r8 /* Workarea intermediate copy buffer */
@@ -71,7 +71,7 @@ ENDPROC(sme_encrypt_execute)
ENTRY(__enc_copy)
/*
- * Routine used to encrypt kernel.
+ * Routine used to encrypt memory in place.
* This routine must be run outside of the kernel proper since
* the kernel will be encrypted during the process. So this
* routine is defined here and then copied to an area outside
@@ -79,19 +79,19 @@ ENTRY(__enc_copy)
* during execution.
*
* On entry the registers must be:
- * RDI - virtual address for the encrypted kernel mapping
- * RSI - virtual address for the decrypted kernel mapping
+ * RDI - virtual address for the encrypted mapping
+ * RSI - virtual address for the decrypted mapping
* RDX - address of the pagetables to use for encryption
- * RCX - length of kernel
+ * RCX - length of area
* R8 - intermediate copy buffer
*
* RAX - points to this routine
*
- * The kernel will be encrypted by copying from the non-encrypted
- * kernel space to an intermediate buffer and then copying from the
- * intermediate buffer back to the encrypted kernel space. The physical
- * addresses of the two kernel space mappings are the same which
- * results in the kernel being encrypted "in place".
+ * The area will be encrypted by copying from the non-encrypted
+ * memory space to an intermediate buffer and then copying from the
+ * intermediate buffer back to the encrypted memory space. The physical
+ * addresses of the two mappings are the same which results in the area
+ * being encrypted "in place".
*/
/* Enable the new page tables */
mov %rdx, %cr3
@@ -103,47 +103,55 @@ ENTRY(__enc_copy)
orq $X86_CR4_PGE, %rdx
mov %rdx, %cr4
+ push %r15
+ push %r12
+
+ movq %rcx, %r9 /* Save area length */
+ movq %rdi, %r10 /* Save encrypted area address */
+ movq %rsi, %r11 /* Save decrypted area address */
+
/* Set the PAT register PA5 entry to write-protect */
- push %rcx
movl $MSR_IA32_CR_PAT, %ecx
rdmsr
- push %rdx /* Save original PAT value */
+ mov %rdx, %r15 /* Save original PAT value */
andl $0xffff00ff, %edx /* Clear PA5 */
orl $0x00000500, %edx /* Set PA5 to WP */
wrmsr
- pop %rdx /* RDX contains original PAT value */
- pop %rcx
-
- movq %rcx, %r9 /* Save kernel length */
- movq %rdi, %r10 /* Save encrypted kernel address */
- movq %rsi, %r11 /* Save decrypted kernel address */
wbinvd /* Invalidate any cache entries */
- /* Copy/encrypt 2MB at a time */
+ /* Copy/encrypt up to 2MB at a time */
+ movq $PMD_PAGE_SIZE, %r12
1:
- movq %r11, %rsi /* Source - decrypted kernel */
+ cmpq %r12, %r9
+ jnb 2f
+ movq %r9, %r12
+
+2:
+ movq %r11, %rsi /* Source - decrypted area */
movq %r8, %rdi /* Dest - intermediate copy buffer */
- movq $PMD_PAGE_SIZE, %rcx /* 2MB length */
+ movq %r12, %rcx
rep movsb
movq %r8, %rsi /* Source - intermediate copy buffer */
- movq %r10, %rdi /* Dest - encrypted kernel */
- movq $PMD_PAGE_SIZE, %rcx /* 2MB length */
+ movq %r10, %rdi /* Dest - encrypted area */
+ movq %r12, %rcx
rep movsb
- addq $PMD_PAGE_SIZE, %r11
- addq $PMD_PAGE_SIZE, %r10
- subq $PMD_PAGE_SIZE, %r9 /* Kernel length decrement */
+ addq %r12, %r11
+ addq %r12, %r10
+ subq %r12, %r9 /* Kernel length decrement */
jnz 1b /* Kernel length not zero? */
/* Restore PAT register */
- push %rdx /* Save original PAT value */
movl $MSR_IA32_CR_PAT, %ecx
rdmsr
- pop %rdx /* Restore original PAT value */
+ mov %r15, %rdx /* Restore original PAT value */
wrmsr
+ pop %r12
+ pop %r15
+
ret
.L__enc_copy_end:
ENDPROC(__enc_copy)